Bros before bros?
by poison-au-coeur
Summary: Human AU where Derek is Scott's older brother and Stiles' boyfriend. Kind of a sequel to my other OlderBrother!Derek fic 'Sleepover'.
1. Chapter 1

Derek was frustrated about how little he got to see Stiles these days. Stiles recently getting the much-awaited spotlight in the field and actually surprising everyone with his lacrosse skills left Derek with little to no time with him.

Stiles was either busy studying for tests or in lacrosse practice. Not that he wasn't proud and happy for Stiles' newly discovered talent, but he missed spending time with him.

To make things worse, his annoying brother was talking about Stiles all the time. And not that he was jealous or anything, but he hated how Scott was still spending time with Stiles in school and in lacrosse practice. _Everyday_.

Derek was looking at Stiles' Facebook page when he hears the front door open.

"Derek! I'm home!" Derek groans as Scott shouts.

"Derek?"

Derek doesn't even bother to answer, his attention back to his boyfriend's timeline. Why were there so many people writing on his wall all of a sudden?

"Derek?" Scott peeks his head through the slightly open door.

"What?" Derek finally responds.

"Just checking if you were home." Scott jumps on Derek's bed.

"Okay. I'm here. Why are you in my room? Get out now!" Derek says, annoyed.

"Ohmygod, you won't believe what happened today at practice!" Scott says completely ignoring his brother.

"I don't really care. So get out." Derek says impatiently, not looking away from his computer screen.

"But it's about Stiles. You know, your…" Scott grimaces, "your boyfriend."

This perks Derek's interest. "Fine. Just tell me already. It's not like anything I say ever stopped you before." he says trying to hide his curiosity.

"So, today, at practice, Stiles totally beat Jackson's ass. He scored like the triple of what Jacks did. It was AWESOME. Like, how didn't anyone know that Stiles was amazing at lacrosse? How did YOU not know?"

Derek growls at that, annoyed at the implication that he doesn't know his boyfriend as well as he should.

"Whatever. Oh, and did I tell you that Stiles is getting pretty popular at school since he basically owned the last match? We went out to grab a bite after practice and there were a couple of girls… and boys from our school that were flirting with him." Scott gives a little mocking smile.

Derek's growls get even louder. He didn't like this at all. Why were there people flirting with his boyfriend, didn't they know Stiles was _his_? And why was his brother spending more time with his boyfriend than he was? Wait, was he actually jealous of his brother? No. Definitely not. Stiles could spend as much time as he wanted with Scott for all he cared.

"By the way, Stiles' dad is working late again so I invited him for dinner. And…" Scott continues talking, but Derek stopped listening after he heard the first sentence.

* * *

"Can't we just order some pizzas or something? I don't want to get food poisoning." Scott mocks him.

Derek had refused to order takeout. He wanted to make a home cooked meal, because… because he was sick of ordering food all the time, plus his mother didn't teach him how to cook for nothing. Yep, this had absolutely nothing to do with Stiles coming over or anything. So Derek had been in the kitchen for the past half hour preparing the lamb chops to perfection and making curly fries, which he knew were Stiles' favorite.

"God, we should have Stiles over more often." Scott teases.

Derek only responds with a hard cold glare.

Scott smirks. "What? You're going to tell me that it's just a coincidence that all of this is Stiles' favorite food?"

"Shut up Scott."

Scott was about to say something back, when the doorbell rings.

"He's here!" Scott smiles, rushing to the door. "Coming!"

Derek grabs a spoon and quickly glances at his reflection, making sure he didn't have anything on his face and that his hair was okay, before he resumes preparing the food, trying to look as casual as possible.

Scott and Stiles walk in the kitchen discussing tactics for tomorrow's lacrosse game.

"So pumped for tomorrow! It's going to be awesome."

Derek turns around and smiles as he sees his boyfriend. "Hey Stiles."

Stiles leans in and gives him a peck on the lips. "Hey creeper."

"Ew." Scott whines.

"The food smells amazing. Oh, are those curly fries? I love curly fries!"

Derek grins as he sees Stiles wet his lips. "It's not ready yet. So you'll have to wait a little."

"That's okay. Stiles and I will just go to the living room and chill. Can you call us when it's done?" Scott is already practically leaving the kitchen.

"Yea, sure." Derek replies, hoping Stiles will choose to stay with him instead.

To his disappointment, Stiles is following Scott out the kitchen. "Thanks Derek."

And just like that, Derek is alone at the kitchen, making the finishing touches to the meal, making sure everything was perfect. He can't help but feel hurt that Stiles just went along with Scott. He wasn't being clingy. He just thought that, since they hadn't seen each other in a while, Stiles would have stayed with him in the kitchen. This whole lacrosse thing was really starting to annoy him. The only thing that was on Stiles' mind was this stupid sport. Not to mention that now his boyfriend was attracting unwanted attention from half of his school.

Derek pours himself a glass of wine and takes a huge gulp. No. He was not going to be the jealous and possessive boyfriend… But what if Stiles felt that they weren't going to work out anymore? Before this Stiles hardly ever got noticed by other people, which is crazy, but Derek knew that it was only because he grew up having Stiles around playing with Scott that he had gotten to see how amazing Stiles was. Now it was different. Stiles was popular. He will start meeting a lot of new people. A lot of new people his age. And they will start growing even more and more apart, until Stiles eventually…

The alarm in the oven startles him. He just shakes out the unpleasant conclusion his mind was about to make. He takes out the lamb chops and sets them on a big dish, takes a last sip of his wine and calls for the boys.

Scott and Stiles rush to the dining room as Derek finishes setting everything up.

"Oh my God, everything looks and smells so good!" Stiles says enthusiastically.

"Yea. Derek is actually a really good cook. He just never ever makes me dinner." Scott sticks out his tongue at Derek.

"Are you complaining? Because there is a very nice TV dinner in the freezer."

"No, no. I'm good, thanks." Scott starts eating before Derek has the chance to change his mind.

"Derek, these curly fries are amazing. Best curly fries ever!" Stiles says, stuffing his mouth with more fries.

"Dude, slow down on the fries. You don't want to get a stomach ache on the day of the final match." Scott says nudging Stiles on his side.

"Yea, yea." Stiles says, not really listening to his friend's advice.

Scott's phone starts to ring. "Hey, it's Allison, I have to get this. I'll be right back." Scott walks out of the living room, leaving Stiles and Derek alone at last.

"So, do you want to sleepover here? A sleepover in my room, of course." Derek says, giving his best smirk.

Stiles bites his lips, but then scrunches up his face. "I can't. Not today. There's that big game tomorrow. I'm just really tired from practice. Rain check?"

Derek frowns. "Stiles, did I do something wrong?"

"What? No. Why would you ask me that?"

"Um.. maybe because you've been completely ignoring me these past few days."

"I haven't been ignoring you. I've been busy with practice. You know that!"

"Well, that isn't stopping you from hanging out with your other teammates! Lacrosse is basically taking over your life!" Derek starts to raise his voice.

"Derek, that's so unfair. I thought you would be happy for me." Stiles says, hurt.

"I am happy for you. In fact, I couldn't be happier."

"Well, that's a very weird way of showing your support. It almost seems like you don't want me to succeed."

"I want you to succeed more than anyone else! I'm so happy that you found something you love, but that doesn't give you an excuse to just neglect everything else that is important in your life."

"I'm not neglecting anything important!"

"Am I not important?" Derek looks upset.

"What? That's not what I meant! What kind of question is that? Of course you are important to me! You know very well that you are -"

Derek cuts him off. "Well, then why haven't you made time for me these couple of days? Why do I feel like even when you are with me, you're still distant?"

"I don't know! I'm sorry if you feel that way, but that's not _my_ fault. I've been busy with practice and school. Jeez, I don't know if you don't remember anymore, but being in high school isn't really a walk in the park." Stiles can feel his hands getting sweaty, his skin getting hotter. He can't believe that they are fighting the day before his big game. He doesn't understand why Derek is blowing this whole thing out of proportions.

"You just don't get it…" Derek says, defeated.

"There is nothing to get. You are being overdramatic. I don't want to have this discussion today. Not right before the big match tomorrow." Stiles is still mad.

"There you go again! All you talk about is lacrosse! All you care about is that stupid sport!"

Stiles can't take this. He can feel Derek starting to get under his skin, he doesn't want to feel guilty for something he didn't do. He doesn't want to fight.

"Okay! Whatever then. Clearly you need some time to clear your head out. I'm leaving. Tell Scott I'll see him tomorrow."

And just like that Stiles gets up, turns his back to Derek and leaves through the front door, without saying another word.

A part of Derek wanted to go running after his boyfriend, to wrap his arms around him, to tell him he was sorry, that he didn't want to fight. But he couldn't swallow his pride. Deep inside he still thought he had all the right reasons to be mad at Stiles.

"Where's Stiles?" Scott asks giving Derek a puzzled look when he returns to the dining room.

"He left early." Derek responds coldly.

"What did you do?"

Derek didn't like his brother's accusatory tone.

"Nothing Scott! I didn't do anything!"

Scott doesn't answer. He doesn't know what to say, which creates a heavy and awkward silence in the room. Making both of them uncomfortable.

"I'm going to my room. Clean up the table when you're done." Derek doesn't even glance up to see the annoyed look on his brother's face, his mind was still going over the fight he just had with Stiles. And even though he was starting to rethink about whether his outburst had been reasonable or not, there was one thing he was sure about; the dinner definitely didn't go according to plan.

* * *

It was the night of the final match. Derek was still annoyed at Stiles about what happened last night, but he was not going to act like a child and not go to the game. Besides, he was slowly starting to feel guilty about the way he just snapped at him. It wasn't like Stiles was deliberately not seeing him. He should have tried to understand Stiles more. He wanted to show him that he did support him.

"Derek! Let's go! We're late." his mother shouts. "I have to take the late shift, again. So we need to hurry. I don't want to miss Scott's last game of the season."

"Okay. I'm all set. Let's go."

* * *

When they arrive, the game had already started. They hurry to the bleachers and take the seats next to Sheriff Stilinski.

"Hey Melissa. Derek." the Sheriff smiled.

Derek was glad that the Sheriff had finally got around accepting his relationship with Stiles. The Sheriff didn't have a problem at all with his son dating a guy, the problem had been that this guy was six years older than his son. It took him two months to finally be okay with their relationship, and now that he finally had, Derek and the Sheriff had developed a very cordial relationship themselves.

"Hello John. Did we miss anything?" Melissa asked.

"Nothing much. The game is tied so far. Scott's been playing great."

"Oh, and by the looks of it, so is Stiles." Melissa returns the compliment.

Both Sheriff and Derek grin proudly. She was right, Stiles was on the field, running around, catching the ball, and passing it around, with the whole school cheering him on. How he kept this talent undiscovered all these years was still a mystery to him.

Derek started to feel even guiltier about the way he acted last night. Lacrosse was clearly something Stiles loved doing, and he couldn't blame him for wanting to spend most of his time practicing. Stiles was finally being recognized and instead of just supporting him, Derek had argued with him about it.

Derek sees that Stiles is now looking at him, waving. Derek smiles, waves back and joins in on the cheer.

The match is over. Stiles had, once more, scored the decisive victory point of the game. A big crowd was now rushing to congratulate the players. Derek slowly made his way towards Stiles, letting a bunch of teenage girls and a few guys rush in front of him to congratulate his boyfriend. Stiles had a huge grin on his face, laughing and high-fiving everyone. He seemed so happy. How could he have been so immature and selfish about something that makes Stiles this happy?

Stiles freezes when he sees Derek, then his face immediately lights up and he rushes towards him.

"You came!" Stiles seems surprised.

"Of course I did. I wouldn't miss your game for anything." Derek gives him a warm smile.

"I didn't think you'd come after what happened yesterday." Stiles looks guilty and apologetic. "And I'm so sorry for what happened yesterday."

Derek frowns. "I'm the one who should be apologizing. Not you."

"No. It's my fault. You totally have the right to be mad at me. I was a lousy boyfriend these couple of days. I'm sorry that I've been so MIA. I really didn't mean to. And I'm sorry that I just walked out yesterday. I was just –"

Derek cuts him off with a kiss. Stiles stiffens, completely caught off guard, but relaxes the moment he feels Derek's warm breath inside his mouth. All the cheering and chatter completely tuned out, Stiles feels Derek's arms embracing his cold and clammy body. He lets out a little whimper when he feels Derek's lips parting. Stiles grabs Derek and pulls him closer, not wanting to let go of the kiss.

"Hey Stiles! You were aweso-" Scott groans as he walks in on his best friend kissing his brother. "Ugh, Derek! You life ruiner!"

Stiles and Derek both chuckle.

"This is not funny! I am going to have nightmares again!"

Stiles looks at his best friend and just shrugs. "Sorry man. The heart wants what it wants." And he leans in for another kiss.


	2. Trick or Treat

"Stiles, calm down dude." Scott says, smiling at his best friend.

Stiles shoots a shocked look at Scott. "How can one be calm on Halloween? This night is going to be totally awesome!" he exclaims, not even trying to contain his excitement, not caring that half of the people in the hallway were looking at him.

Halloween was his favorite holiday of the year. Well, one of his favorite holidays since he couldn't decide between Halloween and Christmas. Christmas was just great because of presents, cozy dinners with friends and family and hot chocolate. But in Halloween, he got to dress up in his favorite costume and eat candy. Lots and lots of candy, and that's pretty hard to beat.

"So what are you dressing up as this year?" Scott asked, as they start making their way to the parking lot.

"Um… Derek and I kind of decided to go as Batman and Robin. I wanted to be Batman, but Derek said he wouldn't dress up if he had to be Robin, which I guess makes more sense. And it's actually better that way since your brother is… you know… big and creepy, while I'm um… not that." Stiles couldn't wait to see Derek in his Batman suit. "Anyways… Robin is pretty awesome too." he adds quickly, before he starts getting too distracted by the image of Derek in nothing but a tight spandex costume.

"Wait. Derek's coming with us tonight?" Scott whines.

"Yeah dude. It will be just like when we were younger, except Derek won't be annoying and teasing us." As Stiles says that he remembers the times when he was just a kid. He and Scott would go trick-or-treating and Derek would tag along to chaperone at his mother's request. Derek would tease them and sometimes steal and eat their favorite candies, not failing to fulfill the role of an obnoxious older brother. As time passed, Derek grew out of the whole Halloween festivities. He no longer dressed up or went trick-or-treating. Stiles, on the other hand, could never really feel too old for such things.

"Speak for yourself." Scott groans. "How did you even convince him to go trick-or-treating? I can't even convince him to give me a ride to school."

"You, my friend, forget that I possess great negotiating skills." Stiles grins smugly.

Scott scoffs. "Uh… whatever. I don't even want to know what you did or promised to do to get Derek to dress up in a costume." Scott scrunches up his face as he starts picturing his best friend having sex with his brother. "Oh god… Too late. I can't get this disturbing image out of my head."

Stiles blushes. "He still doesn't know what it is. It's going to be a surprise."

"Please tell me that he isn't also going to Lydia's party afterwards." Scott looks at his friend, hopeful.

"Um… he isn't going to the party?"

"Really?" Scott's face lights up.

"No. Not really. Of course he's going to be there, you doofus." Scott's smile immediately turns upside down.

"You didn't really expect me to go solo and be the third-wheel for you and Allison, did you?" Stiles snorts.

"Ugh, great. This is going to be so fun. I can't wait." Scott groans.

* * *

The doorbell rings. Scott goes down and opens the door, already expecting to see Stiles. What he wasn't prepared for was what was now standing in front of him. His best friend was in the tightest fitting spandex Robin costume he had ever seen.

"Hey! I look pretty awesome, huh?" Stiles says excited.

"Uh… yeah. I definitely wasn't expecting this." Scott says, smiling.

"Awesome Fred costume." Scott was wearing plain jeans, a white polo, an orange scarf and a blonde wig. He was so glad that Allison had picked costumes that were more... conventional.

"Yeah. Allison is going as Daphne."

"Figured. Is she coming with us?" Stiles asks.

"No. She'll meet us at the party. She's already there helping Lydia out."

"Cool." Stiles smiles. "So… is Derek dressed yet? Where is he?" He looks around and then at Scott expectantly.

"I don't know. I think he is up in his room."

"I'll go get him. Then we can go get some candy!" Stiles says, already halfway up the stairs.

Stiles stops in front of Derek's bedroom and knocks. "Derek. I'm here. Let's go."

When he doesn't hear an answer, Stiles just walks into the room. He gasps as he sees his boyfriend wearing not the classic spandex Halloween Batman costume he was expecting, but one that was reminiscent of Christopher Nolan's version of the dark knight. The only thing missing was a mask, which wasn't a big deal. This was definitely better than the spandex fantasy Stiles was having earlier today. Derek looked _smoking_ _hot_.

"This is so silly." Derek says. And… was he blushing? "Let's just stay in, watch some horror movie, I'll even cook us your favorite dinner. Going out like this is just silly. I feel like such a geek."

"Noooo. You _promised_." Stiles pleads. "And besides, you don't look silly at all. I'm the one with the cheesy costume. You look _hot_."

Stiles walks up to Derek and gives him a little peck on his cheeks. Derek grabs Stiles and kisses his neck.

"Oh yeah? How hot do I look?" he asks softly, still licking and kissing Stiles' neck.

"Ummm. _Very_…" Stiles shakes his head. "No. I know what you are trying to do and I'm not falling for it! Not today! We need to leave if we want to go trick-or-treating before the party."

Derek sighs, defeated. He couldn't say no to Stiles. He tried, but he wasn't very good at it. Actually, it wasn't so much that he wasn't good at saying "no", but Stiles was pretty bad at accepting it as an answer. Either way, he was going. Plus, he was really curious about what the surprise Stiles had planned would be. He already had a general idea of what it was going to be, seeing that Stiles had announced he was going to sleepover after the party.

"C'mon. Let's get out of here so that I can flaunt my hot boyfriend at everyone." Stiles says, tugging Derek behind him.

They go downstairs to meet Scott, whose face turns to utter shock when he looks up at them.

"Oh my god. No. You are not going out like that." Scott says, horrified.

"Why not?" Derek glares at his brother.

"It's embarrassing!" Scott exclaims.

Derek lets out a low growl.

"No it's not. He looks totally badass and hot." Stiles says, defending his boyfriend. "Plus, we don't have time for this. If we want to make it to at least five houses and collect plenty of sugary goods before going to the party we need to leave now."

"You are such a kid." Derek teases, ruffling Stiles' hair.

"Shut up." Stiles says playfully punching Derek on his arm.

Scott just makes a nauseated face. "Ugh… I can't believe this. Just promise me no PDA in front of me!" he says, but Derek and Stiles are already walking out the door, ignoring him.

* * *

They ended up making to six houses before the party. Stiles had already eaten almost all of the candy he had collected on the drive to Lydia's house, which made him more agitated than his normal self.

The boys had just arrived and they were immediately greeted by the red-haired girl dressed in a nurse costume that was just barely on the length of being provocative. Typical Lydia.

"Hey guys. Welcome. I'm so glad you could make it!" Lydia says sweetly.

"Hi Lydia. Nice costume." Stiles responds to his former crush, glad that he no longer harbored any more feelings for her. Actually, ever since he started dating Derek, he and Lydia ended up becoming quite good friends. Who knew, all it took to get closer to her was to get a boyfriend.

"Thanks. Everyone's in the backyard." Lydia says, smiling. "Allison's waiting for you." she adds, looking at Scott, whose face lights up at the mention of his girlfriend's name.

The backyard is already filled with people drinking beer from red plastic cups and dancing… your typical high school party, except it was Halloween-themed.

Stiles spots his teammates in a corner, and decides to go say hi.

"Hey Stiles!" Danny shouts, smiling.

Jackson, who was dressed as a gladiator, turns around and lets out a chuckle.

"Stilinski. What a ridi-" Jackson stops mid-sentence, suddenly looking intimidated, which was weird because Jackson never missed a chance to make a joke on Stiles' expense.

Stiles looks behind him, and sees Derek glaring at Jackson. He smiles smugly.

"Hey guys. You all know Derek, right?" Stiles moves to Derek's side and holds his hand.

"H-hey man. How's it going? Scott's brother, right?" Jackson says, nervously smiling at him.

Derek just nods.

"Yeah. Okay. We'll go find Scott and Allison. We'll talk with you guys later?" Stiles leaves before he can get an answer.

They make their way to the table where the drinks are. Stiles makes himself an impromptu rum and diet coke.

"Do you want me to make you something?"

"I'm driving us back. _Remember_?" Derek says.

Stiles holds both his hands up. "Wow, hold down the sass. I was just trying to be polite."

Derek growls.

Some of Stiles' friends come over to greet them and after an awkward introduction, they start chatting.

Stiles is enjoying himself, pouring himself a few more drinks before he starts to feel a little buzzed. He frowns once he looks at Derek and sees him just standing there, silent.

Stiles grabs Derek's hand and drags him away from his friends.

"Derek, could you stop being, you know… so quiet and grumpy, and try to, I don't know… socialize?"

"You'll excuse me if I'm not really in the mood to socialize with a bunch of teenagers who still drink from red plastic cups."

"Hey!" Stiles gives him his best offended look. "Those teenagers who still drink from red plastic cups happen to be my friends. And if you haven't noticed, I'm also a teenager… who is also drinking from a red plastic cup. It would be nice if you got to know them…" Stiles is trying his best to focus and to sound as coherent as possible. He really wants his friends to get to know Derek.

"Please." he adds.

Stiles is giving Derek the sad puppy eyes. Derek just rolls his eyes and grunts, "Fine."

Stiles makes his way back to his friends. It's only after a while that he realizes that Derek is not beside him. He starts to look around, trying to find his boyfriend.

"Hey, have… have any of you guys seen Derek?" Stiles asks.

"No. He didn't come back with you when you guys went for a talk." says Greenberg.

He starts making his way around the crowd, searching for Derek. Managing to stumble only a few times.

Stiles is starting to worry. What if Derek already left? He wasn't having a good time here, so he probably just left. God, he shouldn't have forced Derek to come. This was all his fault. Why was he so pushy? Why…

That's when Stiles spots Derek, and suddenly he is filled with jealousy and rage.

Derek is standing around three senior girls from his school, who are all over him, laughing at the things he is saying and Derek is smiling at them. _SMILING_! He couldn't believe how _his_ boyfriend was shamelessly flirting with these girls.

"Derek! What do you think you are doing?" Stiles says, marching towards them.

"Stiles-"

"Who is this kid?" a tall blonde girl asks.

"Um… this _kid_ is this _man's_ boyfriend." Stiles answers, with cutting hostility in his voice.

"Excuse us." Derek says as he drags Stiles by his wrist, away from the girls and the crowd.

Stiles is staggering behind, struggling to keep up with Derek's pace. They stop at the end of the pool, far enough from being heard by anyone.

"You're drunk and you're overreacting" Derek says, solemnly.

"No I'm not! I'm totally sober!" Stiles quickly retorts, barely able to stand still. "Okayyyy… okay. So I might be a little tipsy… or a little drunk… or whatever. That still doesn't change the fact that you were totally flirting with those girls!"

"I wasn't flirting!" Derek replies, impatiently.

"Uhhh, I think I know what flirting is when I see it. And _that_, Mr. Sourpants, was flirting!"

"You are being ridiculous." Derek raises his voice. "I didn't even want to be here in the first place. And you are the one who told me to socialize with your friends. Well, I was socializing."

"Don't you dare make this my fault! You are the one in the wrong here!" Stiles yells, his finger furiously jabbing at Derek's chest.

Derek just sighs and grabs Stiles' shoulders, trying to calm him down.

"You have to trust me. I was only making conversation with them. I was just being _friendly_." Derek says, staring at Stiles' eyes.

This seems to calm Stiles down a little. He bites his lips, thinking something over. "Do you promise?" he finally mutters.

"What?" Derek asks, puzzled.

"Do you promise you weren't flirting?" Stiles clarifies.

"I promise." he replies, sincerely.

Stiles locks eyes with Derek for a while before finally mumbling, "I'm sorry."

There is an awkward silence as they both just stand there, not knowing what else to say to each other.

"It's not easy, you know?" Stiles suddenly blurts out.

Derek looks confused, like he did not understand what Stiles was trying to say.

"I know this sounds pathetic, but I don't understand why you are dating me… and, honestly, I'm scared that you will finally realize that you can do so much better -"

"Stiles..." Derek frowns.

"I know I'm being stupid..." Stiles tries to laugh it off, but that makes him look even sadder.

"You're not stupid."

"I just don't think I'm good enough. I hate being this insecure person, but I can't help it that I'm-"

"Shut up!" Derek's frustrated tone startles Stiles. "You need to stop doing this." he adds more calmly.

"Doing what?"

"Stop being so hard on yourself." Derek lets out a heavy sigh. "Stiles... you can't be bringing yourself down all the time. You are good enough. I never thought otherwise. I don't think you realize just how special you are."

"You're just saying that."

"No, I'm not." Derek grabs Stiles, pulls him in and hugs him tightly. He backs away just enough so that he is looking into the boy's eyes. Derek smiles and whispers, "You will always be more than enough for me."

Derek kisses him gently, his tongue softly touching Stiles'. He can taste the alcohol in Stiles' mouth, but he doesn't care.

Stiles is the one to break the kiss, slowly pushing himself away from Derek, but still remaining locked in his boyfriend's embrace. He looks up and whispers sheepishly, "Promise?"

Derek chuckles. "I promise."

"You better not be lying, Mr. Wayne." Stiles says with a dopey smile on his face.

Derek laughs. "Come on. Let's go back home. I hear you have a surprise for me." he grins slyly.

Stiles face blushes. "I don't think I can walk straight all the way to the car."

"Oh, then I guess I'll have to carry you until there." Derek crouches.

Stiles jumps onto his boyfriends back, wrapping his arms and legs around him. Stiles bursts into laughter, realizing how stupid they must look. Robin hanging from Batman's back.

"What?" Derek asks, curious.

"Nothing. It's nothing."

* * *

**Note**: The next part will be the surprise Stiles planned and obviously it will have smut.


	3. Trick or Treat - The Surprise

Stiles could feel his heart beating rapidly. He was so nervous. He was starting to get annoyed that he had sobered up enough on the ride back to the McHale's place.

He didn't know if this was a very good idea after all. What if Derek didn't like this little surprise he planned? God, this was so cliché. A fireman costume? Really? This was probably the most used outfit in all of porn industry. He should have thought of something more original… No, this is not the time for second guesses. This was all he had prepared. Stiles curses himself for not having a plan B. Oh well, it was now or never.

"Trick or treat." Stiles walks out of the bathroom and smirks at Derek who was now only wearing boxer-briefs and a wife-beater.

Derek turns around and when he sees Stiles in his costume he can't help but chuckle.

Stiles' ears start to burn, his whole face is heating up and it turns bright red. He lowers his head, trying to hide his utter embarrassment.

"I knew this was a stupid idea." Stiles mumbles.

"No. No. I'm sorry." Derek apologizes, still grinning. "You look adorable."

"I'm not supposed to look adorable. This is supposed to be… um…sexy." Stiles' voice is barely audible at the last word.

Derek looks at him, smiling. "Come here." he says, reaching out for his boyfriend.

Stiles starts to slowly make his way towards Derek, keeping his eye on the floor, clearly too embarrassed to look at Derek.

When Stiles is close enough, Derek grabs him and pulls him in into his lap.

"You are sexy." he whispers into Stiles' ear, pulling his boyfriend even closer to him.

"You're just saying that because you feel bad for having laughed." Stiles mutters.

"I mean it." Derek reassures him. "You need to learn how to take a compliment."

Derek's face is now nuzzled in Stiles' neck, he breathes in on the teenager's skin, letting out a warm breath that makes Stiles shiver. Derek starts to lick and nip, knowing that he is leaving a bruise on Stiles' neck. He loved doing this, loved marking Stiles to let everyone know that he was _his_. He stops licking and grins when he hears his boyfriend let out a little whimper.

Derek grabs Stiles, throws him in bed and leans on top of him. He starts kissing his neck and makes his way up until he reaches his ears, then he slowly begins nibbling on them.

"Do you really think I'm sexy?" Stiles suddenly asks sheepishly.

Derek pulls himself up, so he is looking directly into his boyfriend's eyes.

Stiles could be so insecure sometimes, it made him sad to think that his boyfriend didn't realize and couldn't see how amazing he really was.

Derek smiles. "Yes." he says sincerely. He lowers himself so that he can kiss Stiles.

Stiles moans are muffled by their kiss. Derek's familiar warm breathe inside his mouth making him forget all about his embarrassment.

Derek slowly starts trailing kisses down Stiles' body.

"You" he kisses Stiles' collarbone.

"Are" he kisses Stiles' nipple.

"Perfect" he kisses Stiles' abs.

Derek is now face to face with his boyfriend's growing bulge.

"Looks like someone's happy." he says, smiling, as he pulls down Stiles' red underwear and lightly pats the erect penis in front of him.

His smile gets even wider as he hears Stiles moan in pleasure.

Derek stops teasing and takes Stiles in his mouth, licking the base of the teen's cock before putting it all in.

Stiles' moans starts getting louder and his grasp on the bed sheets tighter. "Ahh. Derek."

Derek starts to move his tongue around, gently licking, before he gets into a steady pace. Stiles' toes curled, his tight grip now on Derek's hair, pulling him closer. He lets out a needy moan.

"Derek, I- I'm about to-"

Derek abruptly stopped sucking. He got up to meet Stiles' eyes. "I don't want you to cum just yet." he smiled.

"I want to be inside you when you cum. I want us to cum together." Derek whispered softly. "Would you like that?"

"Yea… Derek, I want you inside me. Fuck, I need to feel you inside me." Stiles said with a voice filled with lustful hunger.

Derek easily turned Stiles so that he was on his back. He reached out for the drawer next to his bed, took out a condom, opening the package with his teeth, lowered his underwear and rolled down the rubber until the base of his dick. He spreads Stiles' legs, spits into his hole to lubricate it, and starts teasing by rubbing his dick in the little crack above his butt.

"Derek… _please_." Stiles groans.

Derek can't contain himself much longer. He leans on top of Stiles, wrapping his arms around the boy, as he slowly starts sliding his dick inside him.

Stiles lets out a moan that he muffles by burying his face into a pillow. Derek starts thrusting at an increasing speed, turned on by the noise his boyfriend is making.

"Fuck Stiles, you feel so good." Derek is panting. "Do you like this? Do you like to feel me inside of you?"

Stiles turns his head to the side. "Ahh… Derek… It feels so good. Ahhhh." he moans, tightly clenching the sheets.

Derek nuzzles into Stiles' neck, kissing it. "Stiles. Fuck. Turn around. I want you to look at me when we cum." he said, as he moved back to take out his cock from Stiles' tight little hole.

Stiles was suddenly left with a feeling of emptiness. He wanted… no, needed Derek back inside. He turns around, and his gaze meets Derek's. "Please… Derek… I need you."

Derek smiles and fills Stiles' hole again.

Stiles lets out a moan, Derek's increasing the pace of his thrusts, both of them looking intently into each other's eyes.

Stiles' dick was begging for release. "Derek… I'm going to cum. I can't-"

"Me too. I'm going to cum." Derek moves back, letting his dick slide out, and takes off the condom.

"Oh my God! Ahhh!" Derek cums, leaving trails of his load all over Stiles' stomach.

"Ahhhh." Stiles is panting, as he also cums.

Derek falls on top of Stiles, and he nibbles on his ears before whispering. "I love you."

Stiles pauses and smiles. He smiles because he loves seeing this side of Derek, the soft and more sensible side.

"I love you too" Stiles whispers back. "Mr. Sourwolf." he adds, chuckling.

Derek rolls to his side, grinning, and puts one arm over Stiles' chest.

"So, was the surprise worth going trick-or-treating for?" Stiles asks.

"Hmmm. We should go trick-or-treating everyday." Derek smirks.

Stiles lets out a little laugh, before he moves in closer, feeling the warmth of Derek's body next to his.

And before they know it, they are both asleep, legs intertwined and arms wrapped around each other.


End file.
